The present invention relates to a semiconductor memory device and more particularly a mode selecting circuit for selecting mode of operation of the semiconductor memory device.
A semiconductor memory device is often manufactured so as to perform a special mode of operation to increase its performance. The Dynamic Random Access Memory (DRAM) is manufactured so as to function optionally through one of the various special modes to improve its read/write performance such as fast page mode, static column mode and nibble mode. Conventionally, a particular operational mode is determined by connecting a metal line with the logic circuit for enabling a selected mode through adding a metal masking process during the manufacturing process. Consequently, the metal masking process requires a different masking process, for each operation mode each different masking process, which further requires each different masking layer. If the number of the masking processes and masking layers is increased, not only the production cost is increased, but also problems inherent in the process occur.